"Fifty percent of Americans believe same-sex marriages should be recognized by law as valid, with the same rights as traditional marriages — down slightly from 53% last year, but marking only the second time in Gallup's history of tracking this question that at least half of Americans have supported legal same-sex marriage. Forty-eight percent say such marriages should not be legal."

While there's been little change in the past two years, since Gallup began asking the question in the mid-1990s support for same-sex marriage has risen from 27 percent while opposition has fallen from 68 percent.

The May 3-6 national survey of 1,024 adults has a margin of error of +/- three percentage points on each result.